Generate a sector mask within a big matrix
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A sector mask is defined by distance and angle. Please see the image for clarification on mask.
I want to generate a 100 by 100 matrix where all the matrix element inside the mask is 1 otherwise 0.
Thanks.
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Looky
le 11 Déc 2019
Do you already have the coordinates as show in the image? Then just convert to polar using cart2pol and afterwards use some simple logic to check for radius and the angle.
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Looky
le 11 Déc 2019
Modifié(e) : Looky
le 11 Déc 2019
Solution could look like this:
% Generate example coordinates
x=linspace(-1,1,100);
y=fliplr(linspace(-1,1,100));
[X,Y]=meshgrid(x,y);
% Parameters for sector
angle=10;
radiusIn=.8;
radiusOut=.2;
% Coordinates to polarcoordinates
[phi, rho]=cart2pol(X,Y);
phi=rad2deg(phi);
phi(phi<0)=-phi(phi<0);
% Generate mask
mask=rho>radiusOut & rho<radiusIn & phi>angle& phi<180-angle;
% Have a look at the mask
spy(mask);
For your problem you should exchange the first part of generating the X and Y values for your own coordinates. Otherwise the mask might not be centered the way your data is.
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